1. Field of Invention
The present invention relates in general to the technology of integrated circuit, and more particularly to a parameter control method for an integrated circuit and an integrated circuit using the same.
2. Related Art
After invention of transistor and mass production, all kinds of solid-state semiconductor components, such as diodes, transistors, etc., are used to replace the role of vacuum function in the circuit. In the late 20th century, since the development of semiconductor manufacturing technology, integrated circuits become possible. Comparing with the manual assembly of circuits using discrete individual electronic components, integrated circuit can integrate a large number of micro transistors into a small chip, which is an enormous advance. Production capacity, reliability, modular circuit design method of integrated circuit ensures the replacement for using discrete transistors by standardized integrated circuit design.
Integrated circuits have been widely be used in almost all electrical and electronic equipments or devices, to perform a lot of functions, such as storage, microprocessor, logic, analog and other individual components. Its applications are generally divided into computers and its peripheral equipment, office automation equipments, consumer products, telecommunications, automotive, industrial and so on.
In general integrated circuit, even if the circuits are almost the same, based on different vendors, different applications, they need different setting, such as operating frequency and the like. However, to product those integrated circuits, which have substantially the same operation and different setting, it does not conform to cost effectiveness. Therefore, integrated circuits often provide a specific pin for operation setting. FIG. 1 illustrates the pin diagram depicting the pins of the integrated circuit according to the prior art. Referring to FIG. 1, the integrated circuit 100 is used for power control. The pins includes a gate control pin VG, a current sense pin ICS, a power pin VCC, a ground pin GND, a feedback pin FB and a switching frequency control pin OSC. The gate control pin VG outputs the pulse width modulation signal PWM for controlling the conduction of the main switch. The feedback pin FB is used for receiving the feedback signal. The power pin VCC and the ground pin GND is used for receiving the operation voltage of the integrated circuit 100. The switching frequency control pin OSC is used for determining the operation frequency of the integrated circuit 100 according to the impedance of the frequency determine circuit 101 which is coupled to the switching frequency control pin OSC.
Designer can control the operation frequency of the power control integrated circuit according to the switching frequency control pin OSC. However, one setting of the integrated circuit needs one pin to be occupied. If multiple settings would be set, multiple pins are wasted and the volume of the product would be increased. Thus, Applicants provides a method to use one pin to perform multiple settings.